The Navigator window is located by default just below the Market Watch.
It allows access to the trader’s accounts, Expert Advisors, Indicators, and Scripts.

By pressing the + sign, the Accounts menu expands so the trader may view their accounts and easily switch to the preferred one.

Similarly, by pressing the + sign, the Indicators menu expands so traders may view all available technical indicators.

The same is true for built-in Expert Advisors.
An Expert Advisor (or EA) is an automated set of detailed programming instructions on how to open, modify, and close trading positions without human intervention.

Similarly, by pressing the + sign, the Scripts menu expands so traders may view all available Scripts.

Unlike Expert Advisors, Scripts are executed only once to carry out a specific task.